1. Field of the Invention
This invention relates generally to a portable data scanning terminal and, more particularly, to a hand-held, portable bar code scanning terminal for collecting data scanned from a bar code where the terminal includes a removable and rotatable scanning head to allow for left-handed and right-handed operation.
2. Discussion of the Related Art
Portable, hand-held laser scanners that scan and read light reflective bar codes and other reflective indicia positioned on various types of merchandise and the like are widely available. Many bar code readers of this type usually include a laser scanning unit that is mounted on or within a reader housing, or connected to the reader by a suitable wire connection. The scanning unit includes a laser source, such as a laser diode, that generates a laser beam, and associated optics to focus and direct the laser beam. A reflected beam from the bar code is received by a photodetector associated with the scanning unit so that reflected light intensity patterns can be deciphered. Electrical signals generated by the photodetector that are representative of the light intensity pattern are then processed by processing systems within the reader in a manner that is well understood in the art. The bar code reader is generally equipped with a key pad and display screen so that an operator of the reader can input information, such as quantity of a particular item, and processed information by the reader can be displayed on the display screen.
Many current bar code readers incorporate a compact scanning head or scanning unit secured to the reader. One specific bar code reader of this type is referred to as the PDT 3100 or PDT 3110 available from Symbol Technologies, Inc. of Bohemia, N.Y. By incorporating the entire reader into a single unit, one of the operator's hands is free to operate the key pads while the other hand activates a triggering switch for activating the laser beam for scanning. It has heretofore thought to be desirable to incorporate a scanning unit that can be switched to opposite orientations so as to allow left-handed and right-handed operators to activate the reader while at the same time effectively operating the key pads. In other words, by orienting the scanning unit in a right-handed direction, the right-handed operator can operate the reader and have easy access to the key pads with his left hand. Likewise, by orienting the scanning unit in an opposite direction, the left-handed operator can operate the reader and have easy access to the key pad with his right hand.
U.S. Pat. No. 5,306,900 issued to Metlitsky et al. and U.S. Pat. No. 5,367,152 issued to Krichener et al. both disclose a hand-held bar code scanner that includes a scanning structure mounted on a housing of the scanner that is movable to accommodate both right and left-handed operators. A top wall of the housing is removable and rotatable 180.degree. such that a mirror and associated window of the structure will emit and receive the laser beam from opposite directions. Different mechanisms are disclosed for securing the top wall to the housing.
Although the prior art hand-held bar code readers that incorporate a reversible scanning unit have been at least somewhat successful in meeting the desires of the industry, there is still room for improvement of these types of readers. It is therefore an object of the present invention to improve upon known hand-held bar code readers that incorporate a reversible scanning head.